thank you.. The jack I used was a Philmore No. 504K.. I bought mine at the local Fry's store.
HOWEVER: fair disclaimer.. looks wise I'm pretty satisfied..but it is a bit kludgy if I'm honest.. the jack is meant to go thru and then be secured by a nut on the out side.. I didn't want to grind down the cable exit and so the jack doesn't really stick out of the hole at all, let alone far enough to use a nut. I secured the jack using epoxy which seems to be holding quite well.
The other issue with my approach is that the Sony's have very small about off clearance by the cable exit.. so having the 3.5mm jack flush mounted where mine is will be a challenge depending on the connector size of the 3.5mm cable you want to use.. honestly you will almost certainly wind up with wear marks on the earcup below the 3.5 jack. I am using a 6ft Kabeldirekt cable atm.. which fits (but does rub on the earcup.. however this seems to make the cable less prone to pulling out. =p
I'm happy with my results.. but I feel like the above should be mentioned.. it is possible I may try to find a different jack or give up and grind down the cable exit bit to all securing the jack with the nut.. with the jack sticking further out cable clearance would be improved.